The UK’s first-ever geothermal power plant has just put pen to paper on a ten-year deal that will supply its electricity to 10,000 local homes in Cornwall.

The plant creates energy by mixing water down two wells, one of which is three miles deep, that pass through the Porthtowan zone and the red hot water and granite rocks within.

The United Downs Deep Geothermal Power Project was funded via a mixture of private and public support. Now set to be fully operational in 12 months’ time, Ecotricity, the world’s first renewable energy company, has signed a deal to buy three megawatts of geothermal power for the area.

Geothermal is an exciting form of energy that is currently untapped in the UK. “We’re happy to be part of the project and to add the power to our customer’s energy mix”, said Dale Vince, founder of Ecotricity.

Another buyer came in the form of a local rum distillery, which is preparing a £10 million contract to mature nearly half a million litres of its rum using a geo-heated/powered biome.

Now, why would someone go through the trouble of digging three-mile deep hole when solar panel and wind turbine technologies are advancing as fast as they are?

It’s because geothermal is always running and doesn’t rely on the weather, and while there may be plenty of wind in Cornwall, the sun is not, by any means, a constant.

The owners of the United Downs plant, have acknowldged that while exciting the project is exciting for all involved, it is still very much early days for the plant and any future geothermal developments.

“There’s a huge amount of energy below the surface of the Earth. The limiting factors are the drilling costs and the connections to National Grid on the surface,” said Ryan Law, the firm’s managing director.

Even Ecotricity predicts a growth in the geothermal capacity of the island nation, suggesting in a statement that the national power supply could, and perhaps should, be comprised of 10% geothermal energy.